In a conventional pointer input system, a light spot generated from a pointer generating device is displayed on a display screen, and the image of the display screen including the light spot is then captured by an image pickup device so as to obtain an output data relevant to the light-spot position and display a corresponding output pointer on the display screen. Generally, the image processing method of the pointer input system mainly includes a calibrating method and a tracking method. For performing the calibrating method, a aligning pattern is inputted onto the display screen, and the image of the display screen including the aligning pattern is then captured by the image pickup device to obtain a aligning data. After the aligning data is compared with a predetermined reference data, a space conversion relationship between the display screen and the image pickup device is obtained. For performing the tracking method, the image of the display screen including the light spot is captured by the image pickup device to obtain an output data relevant to the light-spot position according to the space conversion relationship. After the output data is processed by a data processing device, related output pointer is projected onto the display screen through an image projecting system.
Typically, a full-color image contains a variety of colors including for example a red color, a blue color and a green color. Since the full-color image is usually processed according to an arithmetic average or a weighted average of a red color value, a blue color value and a green color value, the characteristic properties of having different signal-to-noise ratios (S/N) and gains in each or composite color channel are not utilized to enhance the image processing capability. Under this circumstance, since the data amount of processing the full-color image is very huge, the image processing efficiency and the data transmitting speed fail to be increased and the stability of the pointer input system is impaired.
Therefore, there is a need of providing an image processing method of a pointer input system for increasing the image processing capability, the image processing efficiency and the data transmitting speed of the pointer input system.